A shaft operated valve—such as a gate valve—typically comprises a shaft provided with a threaded part meshing with a nut of a wedge. Thus, when the shaft is rotated the wedge will be displaced up or down to open or close the fluid passage through the valve.
To ensure that the shaft is axially fixed it is known from e.g. WO 95/19518 A1 to provide the valve housing with a fixed collar meshing with circular protrusions on the shaft. However, such a valve design entails a risk of damaging the wedge, the shaft or the collar when operating the valve—particularly if too much torque is applied during opening or closing of the valve.
Thus, from WO 2014/177681 A1 it is known to form the meshing contact surfaces between the collar and the shaft in a 45° angle in relation to the rotational axis of the shaft to increase the contact surface between the collar and the shaft and thereby increase the friction when the axial force is increased—e.g. when the wedge has reached an extreme position. However this way of axially fixing the shaft in relation to the valve housing is not cost-effective.
Therefore, a valve is needed comprising more cost-effective means for axially fixing the shaft in relation to the valve housing.